This invention relates to a pressure adjustable foam support apparatus and to a method of producing a body supporting structure with adjustable levels of density and firmness (IFD) simulating those of viscoelastic foam or latex foam.
Recently, high density viscoelastic foam has been used in mattresses, mattress toppers and support pads. This material, which was originally developed for NASA, exhibits a slow recovery time after an external pressure is applied to it. Viscoelastic foam products are intended to conform with the contours of the user""s body and provide improved comfort and support. Unfortunately, conventional viscoelastic foam presents a number of disadvantages. Due to its high density (typically in excess of 3 lbs/ft3), this material is quite bulky and heavy. A standard viscoelastic pad typically weighs approximately 3-4 times as much as a comparably sized standard, low density polyurethane foam pad. This makes the high density foam quite difficult and inconvenient to handle, transport and maneuver. The viscoelastic product is also considerably more expensive, about 3-5 times more expensive at the manufacturing level than low density polyurethane foam. Furthermore, conventional viscoelastic foam is not pressure adjustable to meet the individual user""s needs, since it""s cell structure is so tight that it is difficult to deflate, self-inflate, or pass air through the cells. Moreover, if air is vacuumed from a visco foam core, this foam will typically densify rapidly, and become uncomfortably hard.
Various self-inflating and pressure adjustable foam mattresses have been developed. See for example, Lea et al., U.S. Pat. No. 3,872,525, Nissen, U.S. Pat. No. 5,023,133, Bridgens, U.K. Patent No. 984,604 and my previous U.S. Pat. No. 6,038,722. To date, these devices have been particularly designed for outdoor and recreational use. None of the self-inflating mattresses or cushions are suitable for use in conventional indoor, bedroom or healthcare applications. For example, the Lea product is very thin and employed primarily as a camping mat. It is difficult to successfully adjust the pressure in the Lea mattress or to provide for desired levels of comfort because of the relative thinness of the item. If a user is lays upon the Lea mattress with the valve open, the foam cushion fully deflates almost immediately because the mat is very thin (i.e. 2xe2x80x3-3xe2x80x3). It is very difficult, if not impossible, to adjust the pressure and comfort level in either this or the other known products. A user lying on a mat of this type is simply unable to accomplish this. In fact, to date, self-inflating polyurethane foam mattresses have been utilized in only a fully inflated or fully deflated condition. Intermediate air pressure adjustment has not been exhibited in any of these devices. Nor has pressure adjustment been exhibited to date in any indoor foam mattress, mattress topper or healthcare mattress.
There is a good reason that pressure adjustability has not been a factor to date in the design of self-inflating foam filled mattresses. Pressure adjustability is most important for mats, mattresses, topper pads and healthcare mattresses that are designed for indoor use (e.g. beds, mattress toppers, sofas, sofa beds, hospital beds, furniture, etc.). Such support structures are usually relatively thick in order to provide the needed support and comfort levels desired by most persons. Deflating a thick foam pad according to the teachings of the above cited prior art would require super-human strength, as well as wasted time and effort. This has made the use of self-inflating foam impractical for indoor use to date.
Persons desiring custom pressure adjustment have been limited to the use of air bladder mattresses with the mandatory addition of foam layers or mattress covers superposed on the air bladder""s surface to enhance comfort. Sleeping directly on the surface of an air bladder would be very impractical since when fully inflated, it would have sufficient support but feel very hard. Deflated or partially deflated, the bladder would lack the support needed to get a perfect night""s sleep. These types of air bladder structures do not employ foam and do not provide the support, comfort and conformance with the body that is provided by traditional foam, visco or latex foam layers. Air bladders typically fail to keep support when they are deflated or partially deflated and the superposed foam layers above the air bladder also lose support, giving the person the illusion that the surface beneath them is changing firmness. Hence, air bladders gain or lose support, whereas foam, when partially deflated, becomes softer due to a decrease in indentation force deflection (IFD). At the same time the foam maintains support due to an increase in density within the foam core. Notwithstanding this, pressure adjustable foam has not been employed previously due, at least partly, to the problems and limitations described above.
It is therefore an object of the present invention to provide a foam support apparatus that is conveniently pressure adjustable to achieve comfort and support qualities comparable to those of a viscoelastic or a latex foam product.
It is a further object of this invention to provide a pressure adjustable foam support apparatus utilizing a low density foam which functions comparably to viscoelastic foam, but which is much less expensive, much lighter weight and far easier to handle than any viscoelastic support surface, or conventional box spring mattress.
It is a further object of this invention to provide a foam support apparatus that is more comfortable and versatile than any other standard, non-adjustable, comparable density, foam core mattress, mat or mattress topper existing to date.
It is a further object of this invention to provide a foam support apparatus that is quickly and conveniently pressure adjusted to provide multiple desired levels of density, pressure relief and firmness so that the user""s individual comfort and support needs may be satisfied.
It is a further object of this invention to provide a pressure adjustable foam support apparatus which may be partially or fully inflated/deflated and collapsed in a quick and convenient manner by a single person using very little time, effort and exertion.
It is a further object of this invention to provide a pressure adjustable foam support apparatus that is quick, convenient and virtually effortless to assemble, disassemble, transport and store.
It is a further object of this invention to provide a pressure adjustable foam support apparatus that is airtight, impervious to gasses and fluids and which may be washed, pressure cleaned, or directly immersed in water.
It is a further object of this invention to provide a pressure adjustable foam support apparatus that, in certain embodiments is conveniently foldable in distinct sections so that said apparatus may be raised or reclined, as needed and the separate sections may be pressure adjusted utilizing the technology contained herein.
It is a further object of this invention to provide a pressure adjustable foam support apparatus that continuously and sequentially adjusts the pressure within various sections of the mattress so that prolonged engagement of the mattress with the skin and resulting bed sores are avoided.
This invention results from a realization that a relatively low density self-inflating polyurethane foam may be pressure adjusted so that it exhibits a density and firmness comparable to a much more expensive, heavier and non-adjustable viscoelastic or latex foam product. In particular, air is exhausted from or added to the low density foam such that the cellular structure of the foam is modified from its original cellular configuration. By decreasing the volume within the core and, hence, drawing together the cellular structure, this agglomeration of cells increases in density (support) and the firmness (softness/hardness) or indentation force deflection (IFD) of said polyurethane foam is greatly reduced such that these values are equivalent to and provide a consistency, texture and a sensation of touch similar to those of a non-adjustable viscoelastic foam or latex product. A much less expensive, lightweight, versatile, more comfortable and easy to manipulate product is thereby achieved. Nonetheless, the adjustable foam product exhibits advantages and qualities which are comparable to those of the viscoelastic or latex product and is far superior in comfort to comparable low density, non adjustable, foam support devices.
This invention features a pressure adjustable foam support apparatus including a resilient, air pressure adjustable, self-inflating polyurethane foam core and a flexible, airtight cover that encloses the core. One or more air passageways are formed through the covering in pneumatic communication with the foam core. Each passageway carries a valve for alternately permitting and blocking passage of air into and out of the core through the passageway. The valve or valves are opened to at least partially collapse the core and to allow a core that is at least partially collapsed to draw in air through the one or more passageways and expand. The valve or valves are closed to maintain a selected air pressure within the core whereby corresponding levels of density (support) and firmness (comfort) are exhibited by the core.
In a preferred embodiment, the apparatus further includes a vacuum pump or alternating pump communicably engagable with the passageway such that opening the valve engaging the pump with the associated passageway, and operating the pump exhausts air from the core through the open valve and associated passageway to at least partially collapse the core. The passageway may include a first pipe portion disposed within the covering and a second pipe portion attached communicably to and extending transversely to the first pipe portion. The second pipe portion may extend through and be pneumatically communicable with air exteriorly of the covering.
The purpose of said pipe or extended valve structure is to distance the valve and the outer cover from the foam core thereby allowing maximum airflow through the passageway and into the core. It also hinders the foam or inner surface of the outer cover from being drawn into the valve or passageway while the vacuum is evacuating the foam core.
Conversely, conventional and existing foam support structures such as camping mats, would never require the pipe or extended valve disclosed herein. Due to their relative thinness, known foam mats are collapsed and deflated by rolling and/or folding the structure and exerting pressure longitudinally toward the valve and exterior passageway. Air is not drawn out of the core, but instead is pushed out from within the core so the interior surface of the outer cover is not drawn towards the valve and passageway and does not cause a potential occlusion or choking of said passageway.
Another purpose of the pipe mechanism or extended valve feature exhibited herein, is that the mechanism aids in accelerating the self-inflating process of said support apparatus. In order to achieve a rapidly inflated or partially erect product it is desirable for the core to inhale air at a rapid and constant flow. Due to the core""s relative thickness, size and the aggressive suction power exhibited when the exterior valve is opened, the inflating foam layer, segment or component attempts to attract the inner surface of the outer cover extending laterally adjacent to the valve. Because the pipe or extended valve mechanism has a relative transverse and longitudinal thickness, the pipe serves as a spacer and prevents the inner surface of the outer cover from touching the foam components during the self-inflation process. This means there is a space between the inner cover and the foam where air may flow freely.
The pipe or extended valve mechanism may be hard or in other configurations hard and spring-like, and may be the same size or larger than the inner end of the valve. This mechanism may be interengaged within the foam core or located adjacent to the foam core and valve. The pipe may be attached permanently or separably to the back of valve.
A baffle may be disposed adjacent to the passageway and intermediate the foam core and the covering to restrict the covering from being sucked into the passageway by operation of the vacuum pump. The foam core may include one or more interengaged foam layers, segments or components disposed adjacently within the covering.
Within the covering may be attached one or more flexible plastic partitions extending laterally or longitudinally and arranged upright or in planar configuration. These partitions form individual and separate inner partitioned chambers within the covering. Those chambers accommodate respective foam pieces, which are introduced at manufacture. Each foam component may include a respective density and indentation force deflection (IFD) that may or not be different from those of the other foam core. The pump may be attached to the passageway exteriorly of the covering. Alternatively, the pump may be attached to the passageway(s) interiorly of the covering. A vacuum pump may be utilized.
Preferably, the foam core includes a polyurethane foam and the foam core includes one or several foam layers, segments, components arranged in one or several directions within the outer cover. The foam has a density of 1-2.5 pounds per cubic foot and an indentation force deflection of 18 to 65 in a full inflated condition or in its original cellular configuration. Preferably, the core is collapsible to a degree such that it exhibits a density of at least 3 lbs/ft3 and an indentation force deflection of less than 15. The core may include an original cellular structure in a fully inflated condition and a modified cellular structure in the partially collapsed condition, which modified cellular structure is caused by subatmospheric air pressure in at least a section of the foam core. Each level of increased or decreased core pressure or volume exhibits a density (support) and IFD value (firmness) that a person may keep when the desired support and comfort is achieved. The foam core may include one or more interengaged, adjacent, contiguous, superposed, and/or partitioned foam layers, segments or components, which may comprise a planar surface or contain convolute foam patterns. The foam surface may be machined and contain cut-out, concave or convex ribbed surfaces extending laterally and/or longitudinally relative to said body supporting apparatus and disposed within the outer cover. These foam layers, segments or components may be arranged side-by-side longitudinally or laterally. The foam layers, segments or components may be superposed in either laterally or longitudinally extending layers.
This invention also demonstrates how the differing support apparatuses disclosed herein function to meet the users individual comfort needs. Most likely, hospital support apparatuses using the support structure described herein would contain the outer cover. Within and attached to the inner surface of the outer cover may be erect flexible plastic partitions or walls extending transversely, longitudinally, horizontally planar or vertically upright within the outer cover so as to separably partition the foam layers, segments or components. As a result of this, each chamber and the foam therein may be pressure adjusted individually without affecting other separately contained foam layers, segments or components within the outer cover. For example, at home the support apparatus may have two longitudinally extending chambers to enable two persons (or one larger person) to adjust corresponding sides of said support. In a hospital or other indoor setting a mattress may contain laterally extending head, middle body or foot chambers that may be adjusted differently to satisfy diverse medical procedures and patients within the hospital. Alternatively, in a hospital or other indoor setting, a mattress may contain two or more longitudinally extending chambers, which may be controlled by an alternating pump and to offer a wide selection of continuously changing support and firmness levels. Perpetual and ever-changing inner core movement as subtle as it may be, may help in the reduction of pressure ulcers.
One version of this support apparatus features various superposed but distanced chambers wherein top and bottom chambers contain foam and an intermediate chamber contains pressure adjustable air only. The purpose of this embodiment is to raise or lower the core and achieve an adjustable height supporting apparatus that may be contained within the outer cover. The air chamber interposed between the top and bottom foam chambers may be inflated with a double action vacuum which exhausts and blows air. Due to their respective weights the foam chambers stabilize the entire unit and a person may choose the height of said support apparatus by adjusting the air pressure in the internal air chamber. Moreover, each individual foam chamber may be adjusted independently to meet user needs regardless of the height of the support apparatus.
It is also a purpose of this invention to demonstrate how a slow but variable vacuum speed may be desirable to identify and maintain a selected level of density and firmness within the core. Alternatively, a faster variable speed setting may be a desirable and quicker way to evacuate the supporting apparatus. The above variable speed and suction adjustments may be performed with aid of a hand held infra-red remote controller while the person is horizontally juxtaposed on the support apparatus.
Support apparatuses that lack interior dividers within the core meet yet other needs. The foam core may be pressure adjusted simultaneously when the foam layers, segments or components are undivided by plastic layers. Each foam layer, segment or component may include a designated density and indentation force deflection (IFD) that is different from that of the other foam layer(s), segment(s) or component(s). Each foam piece may alternatively have an identical density and IFD.
In an alternative embodiment, the body supporting apparatus may further include either one section or a plurality of longitudinally or laterally juxtaposed and foldably interconnected support sections. Each support section includes a portion of the foam core and a portion of the covering that encloses said foam core portion. The support sections may include a head section that is engaged by the head of a user and a second support section that is foldably attached to and immediately adjacent the head section for supporting a middle of the body. A third foot support section may be foldably attached and immediately adjacent to said second section. These foldably attached sections may be releasably interconnected.
Each support section being releasably interconnected may be assembled in the home using zipper or Velcro(trademark) means to attach these together so as to achieve a foldable and self-inflating support system. Here again, and especially in a healthcare setting, it may be desirable to achieve a raised or reclining head or foot chamber. Since the two or more sections are foldably connected, it is possible to raise and recline each individual section, as well as pressure adjust the individual pieces of the internal foam core to achieve selected support and comfort.
This invention also features a method of producing a pressure adjustable foam support apparatus which includes selected levels of density and firmness. The method includes providing a resilient, air pressure adjustable, self-inflating foam core and enclosing the foam core in a flexible airtight covering. An air passage is provided through the covering in pneumatic communication with the foam core. The passageway carries a valve for alternately permitting or blocking the passage of air into and out of the core through the passageway. The valve is opened to selectively exhaust air from and introduced air into the core through the passageway to adjust the pressure within the core until the core achieves selected levels of density and firmness. The valve may then be closed to maintain the core at the selected levels of density, pressure relief and firmness.
Preferably, the air is exhausted from the core by opening the valve and pumping air from the core outwardly through the passageway. This modifies the cellular structure of the core. The foam core may initially include a density of 1-2.5 pounds per cubic foot and an IFD of 18-65 in a fully inflated condition. The core is partially collapsed by a vacuum pump engaged with the passageway until a density of at least 3 lbs/ft3 and an IFD of below 15 is achieved. As a result, the low density foam core simulates the feel of a high density viscoelastic or latex foam component.
Air pressure may be adjusted sequentially and continuously in a plurality of partitioned foam pieces in the support apparatus. Each piece may be communicably connected through a respective solenoid valve to a vacuum pump that pulls air sequentially through the valve to reduce the air pressure in the foam piece. The respective pieces are pressure adjusted in this manner, in sequence, to generate space between the mattress and the skin. This helps to prevent the formation of skin ulcers and bed sores.